how do I remove all cameraAction
You can remove an action from an object by going to the 'Dopesheet':



Switch to the 'Action Editor' in the Dopesheet header and press the 'x' next to the action name (CameraAction in this case):



This will remove the action from the object selected in the 3D view.

If the action is not used by any other objects it will be removed from the file when the file is saved, closed and re-opened.